Various position sensing input devices are used today to allow an operator to interface with electronic devices such as a computer, PDA, mobile telephones, pocket organizers, portable gaming devices and the like. For instance, a cursor controlled by a mouse has become a necessary tool of the modern computer system. The mouse allows the operator to both operate the movement of an on-screen cursor and execute commands. However, a relatively large input device such as the mouse is impractical to be incorporated into small portable electronic devices. Moreover, such mechanically complex input device is expensive to manufacture and prone to breakage.
Therefore, it is desirable to provide a position sensing device that is accurate and yet small, durable and inexpensive to manufacture.